1. Field of the Invention
The present invention relates to the treatment of soils. More particularly, the present invention relates to selectively removing species of ions from a particular area of soil.
2. Discussion of Background
Using a non-reacting media to carry ion exchange resins is known. Furthermore, the use of electric potentials to induce ion migration is described in U.S. Pat. No. 2,831,804. However, it is believed that an electric potential has not been used in conjunction with ion exchange resins to cause the migration of ions through or from an area of soil.
Collopy, in U.S. Pat. No. 2,831,804, discloses the introduction of direct current to ground water to increase the removal of sodium ions from the immediate area of soil. This method requires leaching to completely remove the sodium ions from the soil.
Several methods exists for removing chemical elements from aqueous streams. In U.S. Pat. No. 4,220,726, Warshawsky uses a macoporous polymer impregnated with a resin to remove metals from an aqueous stream. Similarly, Chen, et al. (U.S. Pat. No. 4,908,137) disclose the use of an ion exchange media bonded to a synthetic polymer for removing heavy metals from aqueous solutions.
U.S. Pat. Nos. 4,578,195 and 4,604,321 disclose the selective removal of mercury ions from an aqueous environment using a mercury-specific agent. Moore, et al. (U.S. Pat. No. 4,578,195) focus on removing trace elements of mercury. Okahara, et al. (U.S. Pat. No. 4,604,321), however, disclose an agent, and method for preparing the agent, which is capable of removing a larger amount of mercury from various gaseous or aqueous media.
Existing methods for chemically treating an area of soil are somewhat limited in scope and generally involve immobilizing, rather than removing or recovering elements from the soil. In U.S. Pat. No. 4,376,598, Brouns, et al. disclose a method of vitrification for immobilizing waste materials contained in the soil. The area of soil is heated, then allowed to cool and harden into a vitreous, solid mass. In U.S. Pat. No. 4,354,942, Kaczur discloses the use of sulfur compounds that react with mercury deposits in the soil to form insoluble compounds which are not removable by elution. Moreover, methods for removing copper from a spill area through the use of zeolites impregnated in a polymer are known.
There is a need for an efficient method of removing chemical elements from a volume of soil.